CA1050040A

CA1050040A - Methods of preparing stable condensation products and products therefrom using an alkylene oxide treatment

Info

Publication number: CA1050040A
Application number: CA223,300A
Authority: CA
Inventors: Kyung S. Shim; Edward N. Walsh
Original assignee: Stauffer Chemical Co
Current assignee: Stauffer Chemical Co
Priority date: 1974-05-28
Filing date: 1975-03-27
Publication date: 1979-03-06
Also published as: IT1035899B; CS183802B2; FR2273028A1; JPS50151801A; US3959415A; GB1513575A; SE425742B; DE2520279A1; NL7506018A; JPS5829797B2; BE829504A; SE7506037L; FR2273028B1

Abstract

METHODS OF PREPARING STABLE CONDENSATION PRODUCTS
AND PRODUCTS THEREFROM USING AN ALKYLENE OXIDE TREATMENT

Abstract of the Disclosure Products which are phosphorus containing oligomers having

Description

Technical Description of the Invention -The present invention is a process for forming improved condensation products of~ -haloalkyl esters of 'O pentavalent phosphorus acids which have flame retardant properties. A number of processes for formation of the class of compounds to be used in the present method are ~os~
described in the patent literature and in ~arious copending applications including the following:
1. U. S. Patent No. 3,513,644 to Edward D. Weil which describes the preparation of polycondensed oligomeric phosphates by heating of tri~(2-haloalkyl~ phosphates.

2. U. S. Patent Nos. 3,641,2a2 and 3,695,925 to Edward D. Weil which describe ~he preparation of oligomeric polycondensed phosphonates from bis(haloalkyl) vinyl phosphonates.

3. U. S. Patent No. ~,896,187 of Edward D. Weil which describes liquid poly(haloethylethyleneoxy) phosphoric acid esters prepared b~ condensing tris(~--~aloethyl) phosphate.

4. Canadian Application 213,382 and U. S. Patent 3,855,359 of Edward D. Weil which describe the copolycondensation of certain phosphates and phosphonates having a 2-haloalkyl group on at least one of these reactants.

5. U. S. Patent 3,822,327 of Edward D. Weil which descri~es homo- and co-polycondensates of bis~2-haloethyl) vinylphosphonates.

6. U. S. Patent 3,891,7~7 of Edward D. Weil which relates generally to condensation products of haloalkyl esters of pentavalent phosphorus acids.
The term "condensation product of a ~-haloalkyl ester of a pentavalent phosphorus acid~ as used herein includes condensation products produced either by self-condensation reactions of such esters or a condensation reaction of such a ~ -haloalkyl ester with other alkyl esters of pentavalent phosphor~s acids.

~-4224 iO50~9~0 The process of this invention is particularly applicable to the homocondensation product of tris(2-chloroethyl) phosphate, the copolycondensation product of bis~2-chloroethyl) vinyl phosphonate and dimethyl methylphos-; phonate, to the copolycondensation product of bis(2-chloroethyl) vinyl phosphonate and trimethyl phosphat~, to the homopolycondensation product of bis~2-chloroethyl) vinylphosphonate, and to the copolycondensation produc~ of tris (2-chloroethyl)phosphate and dimethyl methylphosphonate.
Briefly, the polycondensation products are produced by reacting the l.lonomer (both of which, as has already bPen noted, may be the same) to give off a volatile alkyl halide or alkylene dihalide and leave behind a non-volatile oligomeric condensation produc~.
j The polycondensation reaction can be run without a catalyst, but, to permit lower temperatures and/or shorter reaction times, it is preferably conducted in the presence of a nucleophilic catalyst. Suitable quantities of catalyst are from a few parts per million~ e.gO, 50 p.p.m., up to about 10% by weight, preferably 0.01 - 5% based on weight of the reaction mixture.
The reaction mixture, with proper amount of catalyst, if desired, and in the desired molar ratio of starting materials, is heated to a temperature within the range of from about 110 to about 250C., preferably 160-190C.
Further details concerning the condensation reaction may be found in the disclosures previously mentioned.

~50~4~
It has been suggested in U.S, Patent 3,896,187 of Edward D. ~eil, in Canadian Fatent No, ~08,186, and in Belgian Patent No. 789,851, that xesidual acidity in the type of products of interest herein could ~e removed by treatment of those products with an alkylene oxide neutralizing agent until the free acidic groups in the products, i.e., the residual acid content, was present to an insignificant degree. Alternatively, it has been suggested in U.S. Patent 3,891,727 of Edward D. Weil, that treatment with an alcohol or with water and then with an epoxide be utilized rather than treatment with an epoxide.
However, there was no suggestion in these prior art patents or pending application of using an alkylene oxide treatment after neutralization of the residual acid content had been accomplished for an additional length of time to allow the alkylene oxide to act upo~ acidity liberated by labile groups contained in the condensed product, e.g., pyro, cyclic, and bridged groups, and thereby neutralize any further acidity which would occur by the opening of said groups. This invention is particularly directed to continuing the treatment with an alky~ene oxide alone until labile groups have been opened and subsequently neutralized.
Thus, in accordance with the present teachings, a process is provided for forming a stabilized condensation product formed by condensing a ~-haloalkyl ester of a pentavalent phorphorus acid with itself or with an alkyl ester of a penta-valent phosphorus acid. The process comprises treating the so-formed product with an amount of alkylene oxide for a length of time after residual acidity has been neutralized. The amount of alkylene oxide and length of time of treatment is sufficient to be effective to open labile groups contained in the product and to neutralize these groups.
Any alkylene oxide can be used to act upon the labile groups contained in the product. "Alkylene oxide" is therefore broadly intended to include any compound having an ,1 ~ 4-~f~
.. . ..

lOSO~)~O
oxirane group (i.e., \ C - C / ~. ~llustrative of these compounds are ethylene oxide, propylene oxide, butylene oxide, styrene ~ 4a-~050~
oxide, epichlorohydrin, epibromohydrin, diglycidyl ether, glycidyl butyl ether, glycidyl alkyl ether, glycidyl ether of phenol, diglycidyl ether of resorcinol, glycidyl eth~r of cresol and brominatea cresol, glycidyl esters of acids such as acetic, acrylic and methacrylic acid, glycidol, diglycidyl ethers of bisphenol A and related epoxy resins made from bisphenol, or tetrahalobisphenols and ephichlorohydrin, the diepoxide of dicyclopentylene ether, the diepoxide of vinyl-cyclohexene, the diepoxide of cyclohexenylmethyl cyclohexene-carboxylate, the diepoxide of ~is(cyclohexenylmethyl) aaipate, and the like. The alkylene oxide that is added after residual acidity has been neutralized in the product is used in an amount sufficient to act upon the labile groups contained therein, generally from about 1% to about 10~ by weight based on the total weight of the product.
When a gaseous epoxide, such as ethylene oxide, is employed, it may conveniently be passed in and through the reaction product until the labile groups have been treated. This will generally involve treating the product for about 2 hours to 12 hours, prefera~ly ~rom about 6-11 hours, after neutralization of residual acid content has taken pl~ce, e.g., by preliminary treatment with an alkylene oxide such as described above for 1-4 hours. The unreacted excess which passes through can, if desiredl be collected and recycled. The treatment with alkylene oxide is performed at a temperature of about 90C-140C., preferably 90-110C.
The product formed by the process described herein when incorporated in a polyurethane foam formulation gives a foam having superior green strength to one containing the same product which has not been so treated. Poor green lC~S0~46~
strength is demonstrated by a tacky top surface on the foam and/or a foam which tears easily after the initial cure.
The following working Examples illustrate the invention:

A condensed product of tris (2-chloroethyl) phosphate was formed by heating tris(2-chloroethyl) phosphate in the presence of 0.2% ~a2CO3 at 180C. Ethylene oxide was added at 92-100C for a period of about 4 hours at which time the 0 acetone-water acid number (by methyl red) after 20 min. was about 0.5 mg KOH/g of product indicating neutralization of residual acidity. At this point, however, various labile groups existed, e.g., cyclic, pyro, and bridged groups which would generate further acidity when opened. The ethylene oxid~ treatment was continued for an additional 4 hours to react with labile species and give an acid number of 0.48 mg KOH/g in acetone-water after 20 minutes.

A product similar to that formed in Example I was ~o treated with ethylene oxide at 93-100C. for four hours ~o neutralize residual acidity (acid number = 0.30 m~ KOH/g) and for an additional 5-1/2 hours to reduce the acid number in acetone-water after 20 min. to 0.05 mg KOH/g.

A product similar to those in Examples 1 and 2 was treated at 93-101C. with ethylene oxide for four hours to give an acid number of 0.8 mg KOH/g and for 3.5 additional hours to give an acid number of 0~09 mg KOH/g in acetone-water lmethyl red).

10501~40 A product similar to Example 1-3 was treated for 3.5 hours at 94-103C. with ethylene oxide giving an acid number of 0.8 mg KOH/g. An additional 4 hours gave an acid i number of 0.05.

A series of ethylene oxide treatments were attempted wherein the period of ethylene oxide treatment was maintained only for a period to neutralize residual acidity. The ) treatment temperature was from about 95-110C.

Treatment Time To Neutrallze Sample (hrs) 2.5 j 6 2.2 The products from Examples 1-6 above were incorporated in a polyurethane foam formulation at 10 parts by weight.
The other ingredients were:
) Rea~ents Parts by__eight Niax 16-46 Polyol (Union Carbide) 100 Nlax A-l Catalyst 0.1 N-ethyl morpholine 0.2 L-548 Silicone 1.0 T-10 Stannous Octoate (50~
in dioctyl phthalate) 0.4 Toluene Diisocyanate (80%-2,4 isomer; 20%-2,6 isomer) 50.5 The foam was cured for 10 minutes at 125C and was examined for its physical properties. The Table below sets forth the green strength of the foam. Green strength is a measure of the proper gelation and handling characteristics.

~Q50t~0 Poor green strength is demonstrated by a tacky top surface on the foam and/or a foam structure which tears easily after the initial cure. Condensed products that are not treated in accordance with the present invention, e.g., Samples 5 and 6, demonstrate such inferior physical properties.
Sample from Total Example EO Treatment (Hrs) Green Stren~th 1 8 Good 2 9 Good 0 3 7.5 Good 4 7. 5 Good 2.5 Poor 6 2 Poor Example 8 Tris(2-chloroethyl) phosphate was heated at 165C
to form a condensed product by the process set forth in Example 1. This product was treated with ethylene oxide at 100C for varylng amounts of time. Various samples were used in formulating a polyurethane foam as described in 0 Example 7. The Table set forth below gives the results:

Acid No. In Sample's Water-Acetone at 24 hrs.
Time of Treatment (hrs) (mg KOH/g) Green Strength _ 3 9.5 Poor 6 9 Poor 8 8.7 Poor 3.8 Good 24 6.4 Fair In addition to the particular condensation products descri~ed abo~e, this definition also includes the type of condensation products described in U. S. Patent No. 3,764,640 to Xlose.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process fox forming a stabilized condensation product formed by condensing a .beta.-haloalkyl ester of a pentavalent phosphorus acid with itself or with an alkyl ester of a penta-valent phosphorus acid which comprises treating the so formed product with an amount of alkylene oxide for a length of time after residual acidity has been neutralized, said amount and length of time of treatment being effective to open labile groups contained in the product and to neutralize those groups.

2. A process as claimed in Claim 1 wherein the amount of alkylene oxide which is added after the residual acidity is neutralized is from 1% to 10% by weight of the product.

3. A process as claimed in Claim 1 wherein the alkylene oxide is added for a period of about 3-12 hours after the residual acidity has been neutralized.

4. A process as claimed in Claim 1 wherein the alkylene oxide is added for a period of about 6-11 hours after the residual acidity has been neutralized.

5. A process as claimed in Claim 1 wherein the alkylene oxide is added at a temperature of about 90°-140°C.

6. A process as claimed in Claim 1 wherein the alkylene oxide is added at a temperature of about 90°-110°C.

7. A process as claimed in Claim 1 wherein the alkylene oxide which is added is ethylene oxide.

8. The stabilized products formed by the process of Claim 1.

9. A polyurethane foam containing at least one of the products of Claim 8.